People keep saying that quitting is better to send the message.

Maybe explain why quitting the game (-1 healer in queue) is better at sending a message than doing DF as a different job (-1 healer and +1 tank/DPS) while not resorting to "hit them in the wallet"?

Because if you actually read the OP, you'd know that "hitting them in the wallet" isn't the end goal, the end goal is disrupting their metrics so they actually do something.